自定义ViewGroup实现标签换行（动态创建标签

转载请注明：http://blog.csdn.net/u010419467/article/details/47256041

具体实现步骤： 
1.继承ViewGroup，实现三个构造方法 
2.通过generateLayoutParams给自定义的控件指定参数 
3.实现onMeasure方法 
       a.在这个方法里面首先要做是要知道自己的大小，onMeasure方法会通过父类获取具体的模式和大小。通过getMode方法获得模式（三种模式就不详细说了），然后通过getSize方法获取具体的尺寸。 
       b.通过遍历子控件得到ViewGroup显示时的高度。当子控件（即标签）的宽度之和大于父控件的时候开启行并累加高度 
       c.setMeasuredDimension((modeWidth == MeasureSpec.EXACTLY) ? sizeWidth  
                : width, (modeHeight == MeasureSpec.EXACTLY) ? sizeHeight  
                : height);  方法确定我们ViewGroup最终的大小 
4.重写onLayout方法 
        a.同样的需要遍历子控件，根据宽度控制是否换行。并将每一行的空间用一个列表记录下来，并记录高度从而决定下一行需要显示的位置。 
        b.上面已经将标签以行为单位分别放到适当的list里面。这里就是将list里面的控件显示出来。说到底其实就是一个道理：不管通过什么样的算法，只要知道子控件正确的显示位置即可。 
        c.确定完位置后调用child.layout(lc, tc, rc, bc);  方法将它画出来即可。需要注意的地方是最后一行我们需要特殊处理。通过上面的判断我们实际的最后一行是永远不会大于ViewGroup的宽度的，而这一行的高度同样需要记录下来 

完整的代码如下： 

public class MyFlowLayout extends ViewGroup {public MyFlowLayout(Context context, AttributeSet attrs, int defStyle) {super(context, attrs, defStyle);// TODO Auto-generated constructor stub}public MyFlowLayout(Context context, AttributeSet attrs) {super(context, attrs);// TODO Auto-generated constructor stub}public MyFlowLayout(Context context) {super(context);// TODO Auto-generated constructor stub}public void setData(String[] data,Context context,int textSize,int pl,int pt,int pr,int pb,int ml,int mt,int mr,int mb){createChild(data,context,textSize, pl, pt, pr, pb, ml, mt, mr, mb);}public void setData(List<String> data,Context context,int textSize,int pl,int pt,int pr,int pb,int ml,int mt,int mr,int mb){String[] mydata = null;if(data!=null){int length = data.size();mydata = new String[length];for(int i = 0 ; i<length;i++){mydata[i] = data.get(i);}}setData(mydata,context, textSize,pl, pt, pr, pb, ml, mt, mr, mb);}private void createChild(String[] data, Context context,int textSize,int pl,int pt,int pr,int pb,int ml,int mt,int mr,int mb){int size = data.length;for(int i = 0;i<size;i++){String text = data[i];TextView btn = new TextView(context);btn.setClickable(true);btn.setGravity(Gravity.CENTER);btn.setText(text);btn.setTextSize(textSize);btn.setPadding(dip2px(context, pl),dip2px(context, pt),dip2px(context, pr),dip2px(context, pb));//btn.setTextColor(0xff67c530);btn.setTextColor(getResources().getColorStateList(R.color.selector_button_tc));btn.setBackgroundResource(R.drawable.mark_green);MarginLayoutParams params = new MarginLayoutParams(MarginLayoutParams.WRAP_CONTENT,MarginLayoutParams.WRAP_CONTENT);params.setMargins(ml, mt, mr, mb);btn.setLayoutParams(params);btn.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {//clickMark(btnText);}});this.addView(btn);}}interface MarkClickListener{}/**      * 根据手机的分辨率从 dp 的单位 转成为 px(像素)      */      private int dip2px(Context context, float dpValue) {          final float scale = context.getResources().getDisplayMetrics().density;          return (int) (dpValue * scale + 0.5f);      }  @Overridepublic LayoutParams generateLayoutParams(AttributeSet attrs) {return new MarginLayoutParams(getContext(), attrs);}@Overrideprotected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {super.onMeasure(widthMeasureSpec, heightMeasureSpec);int widthMode = MeasureSpec.getMode(widthMeasureSpec);int heightMode = MeasureSpec.getMode(heightMeasureSpec);int widthSize = MeasureSpec.getSize(widthMeasureSpec);int heightSize = MeasureSpec.getSize(heightMeasureSpec);int childCount = getChildCount();int lineWidth = 0;int lineHeight = 0;int width = 0;//warpcontet是需要记录的宽度int height = 0;for(int i = 0 ; i< childCount;i++){View child = getChildAt(i);// 测量每一个child的宽和高 measureChild(child, widthMeasureSpec, heightMeasureSpec);MarginLayoutParams lp = (MarginLayoutParams) child.getLayoutParams();int childWidth = child.getMeasuredWidth()+lp.leftMargin+lp.rightMargin;int childHeight = child.getMeasuredHeight()+lp.topMargin+lp.bottomMargin;if(lineWidth+childWidth>widthSize){width = Math.max(lineWidth, childWidth);//这种情况就是排除单个标签很长的情况lineWidth = childWidth;//开启新行height += lineHeight;//记录总行高lineHeight = childHeight;//因为开了新行，所以这行的高度要记录一下}else{lineWidth += childWidth;lineHeight = Math.max(lineHeight, childHeight); //记录行高}// 如果是最后一个，则将当前记录的最大宽度和当前lineWidth做比较              if (i == childCount - 1)              {                  width = Math.max(width, lineWidth);  //宽度                height += lineHeight;  //            }}setMeasuredDimension((widthMode == MeasureSpec.EXACTLY) ? widthSize                  : width, (heightMode == MeasureSpec.EXACTLY) ? heightSize                  : height);}/**      * 存储所有的View，按行记录      */      private List<List<View>> mAllViews = new ArrayList<List<View>>();      /**      * 记录每一行的最大高度      */      private List<Integer> mLineHeight = new ArrayList<Integer>();  //onLayout中完成对所有childView的位置以及大小的指定@Overrideprotected void onLayout(boolean changed, int l, int t, int r, int b) {mAllViews.clear();  //清空子控件列表        mLineHeight.clear();  //清空高度记录列表        int width = getWidth();//得到当前控件的宽度（在onmeasure方法中已经测量出来了）                int childCount = getChildCount();        // 存储每一行所有的childView          List<View> lineViews = new ArrayList<View>();          int lineWidth = 0;  //行宽        int lineHeight = 0; //总行高        for(int i = 0 ; i<childCount;i++){        View child = getChildAt(i);        MarginLayoutParams lp = (MarginLayoutParams) child.getLayoutParams();//得到属性参数        int childWidth = child.getMeasuredWidth();        int childHeight = child.getMeasuredHeight();        // 如果已经需要换行          if (childWidth + lp.leftMargin + lp.rightMargin + lineWidth > width)  //大于父布局的宽度        {          // 记录这一行所有的View以及最大高度          mLineHeight.add(lineHeight);          // 将当前行的childView保存，然后开启新的ArrayList保存下一行的childView          mAllViews.add(lineViews);          lineWidth = 0;// 重置行宽          lineViews = new ArrayList<View>();          }           /**              * 如果不需要换行，则累加              */              lineWidth += childWidth + lp.leftMargin + lp.rightMargin;              lineHeight = Math.max(lineHeight, childHeight + lp.topMargin                      + lp.bottomMargin);              lineViews.add(child);          }        // 记录最后一行  (因为最后一行肯定大于父布局的宽度，所以添加最后一行是必要的)        mLineHeight.add(lineHeight);          mAllViews.add(lineViews);          int left = 0;        int top = 0;        int lineNums = mAllViews.size();        for(int i = 0;i<lineNums;i++){         // 每一行的所有的views              lineViews = mAllViews.get(i);              // 当前行的最大高度              lineHeight = mLineHeight.get(i);              for(int j = 0 ;j < lineViews.size() ; j++){            View lineChild = lineViews.get(j);            if(lineChild.getVisibility() == View.GONE){            continue;            }            MarginLayoutParams lp = (MarginLayoutParams) lineChild.getLayoutParams();            //开始画标签了。左边和上边的距离是要根据累计的数确定的。            int lc = left + lp.leftMargin;            int tc = top+lp.topMargin;            int rc = lc+lineChild.getMeasuredWidth();            int bc = tc+lineChild.getMeasuredHeight();            lineChild.layout(lc, tc, rc, bc);            left += lineChild.getMeasuredWidth() + lp.rightMargin + lp.leftMargin;            }            left = 0;//将left归零            top = lineHeight;        }        }

调用方法：

@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);MyFlowLayout myview = (MyFlowLayout) findViewById(R.id.myview);String[] myData = {"one","two","dkfjdkf","kdfkdfj","jdkfdfkjdkfdkfkdkdfj","kdjkfdjkjkjskkjkd"};myview.setData(myData, this, 15, 10, 10, 10, 10, 10, 10, 10, 10);}

下载连接：点击打开链接

希望爱好编程的小伙伴能加这个群，互相帮助，共同学习。群号： 141877583

下面有附件中不需要积分